Elevator car operation to serve special status calls



June 8, 1965 J. E. MAGEE 3,187,343

ELEVATOR CAR OPERATION TO SERVE SPECIAL STATUS CALLS Filed May 12. 1961 .2 sheets-sheet 1 JH/vE/VGEE.

June 8, 1965 J. E. MAGEE 3,187,843

ELEVATOR CAR OPERATION TO SERVE SPECIAL STATUS CALLS Filed May 12, 1961 2 Sheets-Sheet 2 /Pa 14 595 14 /Pc 14 SELECTOR MACH/NE Wifi l i f v ono/N6 Co/vr/POLS 72 70 75 COL/NTE@ CQPC M /@a WEG E-f:

fa/E2@ [gi/15 l' 77 f fmv CAE G W It 211:15 [k12 CHEO' (iL/202 A A la INVENTOR. 5&5. bm/M655 United States Patent O 3,187,843 ELEVATOR CAR OPERATION T SERVE SPECIAL STATUS CALLS John E. Magee, Greenburgh, NY. (191 Forest Blvd., Ardsley, N.Y.) Filed May 12, 1961, Ser. No. 109,558 16 Claims. (Cl. 187-29) The invention relates to control systems for one or more elevators.

It is attempted in present-day elevator systems to provide yan equitable division of service during periods when maximum quality of service is economically unattainable, such as during the evening peak exodus of the building tenancy. To this end, zoning arrangements, preference return .and various spotting arrangements have been devised. A criterion of this trac condition is occurrence of a b-y-pass condition of one or more cars dictated by capacity or near capacity loading at upper floors. Another criteri-on of this tratlc condition is the existence of one or more registered down landing calls which have been unanswered for more than a normal length of time.

In accordance with the invention, a criterion of the down peak trailic condition, such as .by-passed down landing calls or registered down landing calls which have been unanswered for more than a predetermined length of time (long wait calls), is employed to transfer one or more elevator cars from the -type of operation existing before a down peak exists to a type of operation in which the transferred car or car-s answers progressively lower Ibypassed or long wait down registered calls.

The preferred embodiment of the invention disclosed herein involves detection of this by-pass condition to initia-te ,a sequence of reversals of a car or some of the cars as progressively lower landings where such by-passed calls `are registered. A more equitable division of service with respect to demand originating at middle or lower floors of Va building will result. One or more cars may be retained on their original pattern of ope-ration through trip or high call reversal, to avoid depletion of service at upper floors.

Therefore, it is an object of this invention to provide a control system for one or more elevators in which service to lower doo-rs in the buildingr will be on an equitable basis during period of peak down traflic.

`It is a further object of the invention to provide exible assignment transfer means to accommodate varying degrees of the severity of the peak and to provide for the con-tingency where a car may be temporarily out of servicee. In the preferred embodiment of the invention, as disclosed herein, it will be assumed that the installation comprises a group of at least three elevator cars, but it will be understood Iby those skilled in the .art that the invention `is applicable to a different number of cars. In carrying out the invention according to the preferred embodiment circuit means are provided for each car for detecting when each registered down landing call is bypassed 4by tha-t car. Such by-pass by .any car of the group is then remembered on a group basis for each landing of a by-passed call. A certain number of such remembered by-passed calls causes transfer of lassignment of one ear to permit it to terminate its following ascent at the highest of such calls. Persistence of remembered lay-passed calls for a certain period or existence of a greater number of remembered by-passed calls will cause a similar assignment transfer of a second car of the group. These two cars then will reverse their upward travel at progressively lower remembered vby-passed down landing calls until all such calls have been served. A raking action of all such calls thus results. During this period the third car of the group continues to respond to upper iloor demand on its original basis, either through trip or limited by highest registered call, as the case may be. However, its Iby-pass call detection circuit i-s inoperative during transferred operation of either other car, to prevent any overlapping upward travel by them during the period of transferred oper-ation.

Provision is also made in the invention `for suitable transfer response if any car of the group is removed from service. This would limit by-pa-ssed call reversal to a single car and retain one for service to upper floors.

`In conjunction with the invention certain refinements of operation in other areas are desirable. A car subject to transferred assignment will by-pass up landing calls during its ascent. Similarly its lobby hall lantern or direction-to-load sign will be isolated during the transferred operation.

Features and .advantages of the invention -will be seen from the preceding and from the following description of the operation of the preferred embodiment which should be considered in conjunction with the accompanying drawings in which:

FIG. l is a simplied schematic wiring diagram of the circuits for detection of by-passed down landing calls by any car of the group and the group memory circuits forming part thereof;

FIG. 2 is a simplified schematic wiring diagram of operation transfer circuits controlled hy the quantity of remembered by-passed calls and time of persistence;

FIG. 3 is a simplied schematic wiring diagram of reversal determining circuits for cars a and b depending on highest remembered by-passed call;

lFIGS. 4, 5, 6 and 7 are simplified schematic wi-ring diagrams showing complementary control changes utilizing elements of the invention; and

FIG. S is a schematic diagram illustrating, in general,

the type of elevator system to which the invention may be applied.

For purposes of simplication the invention will be described by reference to and operation in conjunction with the system of control described in my Patent No. 2,944,634. It will be understood, however, that this association is merely for purposes of illustration and that the invention is equally applicable with many other types of elevator control systems.

FIG. 8 illustrates in schematic :form a well known elevator system, such as the type illust-rated and described in United States Patent No. 2,944,634, and comprises, for example, three c-ars a, b and c, each of which is equipped with the usual operating panel 1G having flood selection push buttons, etc. and with a load responsive switch LSa, LSb and LSC, respectively. The cars are raised and lowered by a hoisting rope 11 having a counterweight 12 attached thereto and which passes over a traction sheave 13 rotatable by a hoisting motor MAa and controlled by a brake BRa. The conventional selector machine 14 may be operated from the motor shaft or by a separate, known type of selector drive. The selector machine 14 is modified with respect to the machine described in Patent No. 2,944,634 in the manner hereinafter described. For the sake of simplicity, floors 5 through 12 are not illustrated in FIG. 8, but these doors, as well as the floors illustrated, are equipped with hall push buttons 15 for permitting calling of a car by a floor or hall prospective passenger.

The progressively lowered reversal of the invention may be placed in operation by such means as a discrete program change in certain systems, or Iits initiation or reversal points may be dictated by other forms of demand -for privileged service, such as by a plurality of key 0perated landing switches.

In the description hereinafter given, it will be asareas/rs sumed that the elevator system comprises the circuits, controls, mechanisms, etc. set forth in said Patent No. 2,944,634 modiiied as set forth hereinafter to include .the circuits and controls of the present invention. Accordingly, the description of the operation of the system set forth in said Patent No. 2,944,634 will not be repeated herein, and the description and drawing will herein be limited t-o the modifications of the system set forth in said Patent No. 2,944,634 required for my present invention and t-o certain portions of the sys-tem of said Patent No. 2,944,634 with which the modifications cooperate. Except for such modifications as are hereinafter dcscribed, i-t will be understood that the system of the invention operates as described in said Patent No. 2,944,634. For convenience, the symbols diagram conventions, etc. employed in said Patent No. 2,944,634 will be used herein. Additional electromagnetic switches employed in the preferred embodiment disclosed herein are as follows:

3RR through iSRR-down by-passed call memory switches RVR-reversal `assignment switch RVRT-reversal assignment time switch RVRX-auxiliary reversal assignment switch Additional selector machine components employed in the preferred embodiment disclosed herein are as follows:

Brushes: RRE, RHB Stationary contacts: RR3-1S, RH3-15 Additional contacts are employed on certain electromagnetic switches of said Patent No. 2,944,634 and are utilized lin circuits of this invention. In each such case, the reference let-ters and numerals clearly associates them with their .activating coil shown in said Patent No. 2,944,634. All such contacts maybe readily identified by the absence of the letter R in their designations. All circui-t elements entirely new to this disclosure include a letter R in their designations.

To simplify the following description cer-tain assumptions have been made. Car a is selected as continuously available for transfer to the reversal control of the invention, .that is arranged as the initial carto so respond. Car c is arranged without `such transfer facilities and car b has been selected to show the operation wherein a car may serve in either of the foregoing categories. in this connection, it will facilitate the description to refer to the reversal control of said Patent No. 2,944,634 as the parent reversal control, that is, that provided by circuitry of XH switch in said Patent No. 2,944,634.

FIGURE V1 Selector contacts BH2 through DH1? described in said Patent No. 2,944,634 are repeated in FIG. 1 for clarity, and new selector machine brushes DPBR, like the selector machine brushes DPB of said patent, have been added. From .said Patent No. 2,944,634 it is known that each down landing call while in'registration will cause energization of its -associated DH selector contact from a B-lsupply feeder, and such is the case for contacts DHiSa, lDill'Sb and DHiSc. Assume synchronous selector brushes DPBRa and RRBa of downward by-p-assing car a contact selector contacts BHiSa and RRlla, respectively. A circuit will be completed from the energized DHlSa selector contact through brush DPBRQ, blocking rectifier RRFa, non-stop switch contacts NSM, car in service switch contacts CSea, down direction `switch conlfacts DNQa, iield and brake switch contacts Hiia, brush RRBLI, selector contacts RRia and coil iSRR to energize relay iSRR. Contacts iSRRi close to complete a selfholding circuit for relay iSRR until such later time as response to the initiating registered call causes de-energization yof contact DHtlSa.

This constitutes detection and memory of a down landing call which is by-passed by a non-stopping descending elevator. In a similar manner by-pass of either car b or car c in a downward direction could result in detection :and memory of the event, this assuming, for the time, that contacts of reversal assignment switch RVR and auxiliary reversal assignment switch RVRX are properly disposed.

if desired, detection and memory circuits kfor certain lower iioors may be omitted on .the assumption passengers walk down during peak traflic. Similarly, corresponding circuits for upper oors may be omitted in view of the fact that car c will not, as disclosed herein, be subject to reversal of the invention and can be expected to adequately serve those floors.

Y `FIGURE 2 Reversal assignment switch RVR is actuated in response to a nominal number of remembered by-passed calls, say two, generally indicative of by-piass from a landing low in the building. The Values of resistors R3Rf-R15R determine the number of bydpassed calls required to operate relay RVR, and series resistor RVRR and contacts RVR3 permit adjustment of therelease or drop out excitation of the relay. Assume RVR holds `until all RR contacts have opened. lReversal assignment time switch RVRT is delayed in operation, such as by a gas escapement mechanism, until a predetermined time after closing of RVR4 contacts. Auxiliary reversal assignment switch RVRX will operate in response to some greater number of remembered by-passed calls, say six. Persistence of a lesser number for a time sucient for RVRT oper-ation or nonstop action of more than one car can introduce resistor RVTR `to permit a lesser number of remembered bypassed calls, say four, to cause actuation of RVRX switch. if car c is not in service, contacts CS7c open and operation of RVRX is prev-ented.

IFIGURE 3 `Closing of contacts ofthe reversal assignment switches RVR and RVRX of FIG. 2 can here be seen to provide an enabling circuit for cars a and b which permits actuation of their XH relays to occur at the highest remembered by-p-assed call. The result of XH operation as disclosed in said Patent No. 2,944,634 is to initiate stopping at the il'oor approached when XH operates and to cause reversal ,of direction for downward travel from that iioor.

Assume that the previously assumed two remembered {by-:passed calls for actu-ation of RVR exists at floors 3 and 4. yCar a if travelling upward without car calls would then be caused to reverse at the uppermost of these calls, or at the fourth landing, The circuit would extend from the positive terminal of the power source through alll higher memory switch back contacts, 15RR4 through 5RR4, through selector contact Iii-i461, brush RHBa, contacts RVRS, CSa, Uilia, backcontacts HCCda and switch 4coil XI-la to the negative terminal of the power source. Similarly, for a greater number of remembered by-passed calls contacts RVRX3 would be closed enabling operation of XHb upon approach to the uppermost of such cal-ls independent of higher registered calls ortop terminal demand which govern parent reversal determining circuits of the reference patent. Although parent circuitry for actuation of XH may be incomplete due to higher registeredrhall calls, the circuits of the invention prepared by contacts RVRS or RVRX3 closing permit XH Vactuation independent of higher registered calls which have not attained remembered by-pass status.

FIGURE 4 When reversal assignment switch RVR is operated its normally closed contacts RVR6 and RVR? are openedV to isolate the up landing call pickup brushes UPBa and tinuously illuminate its lobby lantern or car-up sign during transferred operation of car n and/ or car b. A similar lantern control is well known in the art for zoning systems of elevators.

FIGURE 5 `Introduction of an RVRS normally closed contact in this circuit voids `selection of any car at the lower terminal while any car is subject to remembered by-passed call reversal operation. As a consequence lobby up lanterns would not be operative for cars a and b since such devices where used normally depend on selection.

IFIGURE 6 Introduction of an RVR normally open contact `such as contact .RVR9 for car a, RVR10 for car b, and RVRll for car c, in the start initiation circuit of eac-h elevator control permits departure upward from the lobby independent' of a yselection operation, that is in a manner similar to departures from intermediate landings.

FIGURE 7 RVRIZ and RVRX4 contacts arranged in the indicated circuits of the reference patent, for cars a and b respectively, void through trip or upper zone restrictions of the reference patent as applied to a car actually assigned to reverse in Iresponse to remembered by-passed calls. HCC3 contacts of FIG. 3 then will be opened only if a car call in the specific car is actu-ally in registration.

Detection restriction Returning `to FIG. 1, it may be seen that for cars b and c reversal assignment switch contacts exercise control in the detection circuits, that is between DPB and RRB brushes. These prevent detection, and consequent memory, of down calls lby-passed by cars which are not subject .to remembered by-passed call reversal whenever another car or car-s is so subject. When car b becomes subject to remembered bypassed call reversal the auxiliary reversal assignment switch cont-acts RVRX1 restore the facility .of the detection and memory .circuits of car b to detect and cause memory of down calls by-passed by car b.

Group operation A more complete understanding of the invention may best be had from a description of the operation as applied to the three car group, elected for this disclosure.

As datum conditions assume all cars in service with cars a and b located at the lower terminal, as indicated in drawings, with car b selected as next to leave upward. Assume further vthat car c in descending non-stop from a point above the fourth landing bypasses registered down landing calls at both fourth and third landings. As eX- plained in said Patent No. 2,944,634 these registered calls result in energization of selector contacts DHdc (not shown) and DHSc, respectively. Car c in by-passing these calls would cause actuation of memory switches 4RR (not shown) and SRR the circuit in the latter case, for instance, extending from BH3C through lbrush DPBRC in passing, through rectier .RRFQ contacts N830, CS60, RVR2, DN9c .and H130, all closed for conditions assumed at .this time, through brush RRBc to contact RRSC in passing, through connecting Wires to RR3b and RR3a and thence through the coil of switch SRR to supply line B, energizing coil SRR to cause yactuation of that switch. Just previous to such action, when passing the registered down call at the fourth landing, switch 4RR (not shown) would have been actuated in .a similar manner. Each of these switches is .sustained through contacts such as SRRl until recognition and cancellation of its associated down landing call with consequent de-energization of its DH selector contacts, .such as DHSa, DHSb and BH3C.

Actuation of switches 3RR and 4RR permits sucient current to flow through resistors RSR and R4R to energize coil RVR suiciently to actuate that switch, for the previously assumed operating requirement. Contacts RVRI and RVRZ separate to prevent detection of by-passed calls by cars b and c. Contacts RVR3 determine the release value of switch RVR. Contacts RVR4 result in energization of coil RVRT but the associated switch is delayed a predetermined time before actual operation. Contacts RVRS (FIG. 3) prepare the reversal determining circuit for car `rz for actuation at a landing above which no remembered bypassed down landing calls exit. The chain of RR4 back contacts will be seen to govern this, independent of parent control circuits of switch XH. Normally closed RVR6 and RVR7 contacts open to prepare for by-pass of up landing calls by cars a and b. Normally closed contacts RVR8 open to isolate lobby selection of all cars and normally opened contacts RVR9, RVRM and RVRll close to permit departure of all cars from the lobby to be in a manner similar to that from intermediate oors, that is, independent of any selection or scheduling mechanism. Cars a and b both are thus permitted to leave the lower terminal independent of prior selection of car b, as assumed earlier, provided their normal door open dwell periods have expired.

Thus, following upward depart-ure of car a from the lower terminal and approach to the fourth landing switch XH will be caused to operate to initiate stopping and reversal to down travel at that floor. Upon selector brush RHBa contacting selector contact RH4a a circuit is completed from the positive terminal of the power source through the chain of closed RR4 contacts above RH4a, 15RR4 through 5RR4, through RH4a, brush RHBa, contacts RVRS, UPlSa, CS7a, HCCSa, all in closed position at this time, and through the coil of switch XH to supply negative terminal to cause actuation of that switch. This as explained in said Patent No. 2,944,634 results in stopping of car a at .that floor and reversal of direction for downward travel with the consequent cancellation of the down call at that floor. As a result of such call cancellation the portion of the holding circuit for switch 4RR which caused DH4a to be energized is now interrupted. As a result switch 4RR is released, without effect at this time since it was assumed that RVR once operated would be retained by a single feed circuit, such as that still provided -by contacts 3RR2.

Assume now that car a becomes fully loaded at the fourth landing and as a result by-passes the third landing during its descent. After a normal unloading time at the lower terminal, it would ascend again and respond to the remembered by-passed call at the third landing by stopping and reversing there and cancelling the registered demand for down service from that point. As a result switch SRR would drop out in turn interrupting its sustaining feed for RVR switch coil.

While switch RVR was actuated as described all cars would have departed from the lower terminal in a manner similar to their departures from intermediate landings. Upward termination of travel of cars b and c would be as determined by control of parent circuits for their XH switches as disclosed in said Patent No. 2,944,634. Cars a and b would travel non-stop upward, Vlay-passing registered up landing calls, this action being justified for car b in anticipation of its transfer to a reversal operation as described for car a. Circuits for detection of by-passed down calls by cars b and c are opened to avoid higher by-pass of either of these cars when travelling downward from affecting the reversal point of car a. The lower terminal lanterns, or This Car Up signs, of cars a and b would not light when respective cars were at that terminal but the similar indicator light for car c would be continuously illuminated (not shown). As a result car calls in cars a and b are avoided and HCC3 contacts of FIG. 3 are closed, and contacts RVRIZ opening have erased through trip control of HCCa.

Assume now that with car a at the lower terminal and car b approaching it that car c in descending by-passes calls for downward service at six landings, say, 15th, 14th,

aisasss y 11th, 9th, 6th and 4th ioors. Assume further that in the following response to these calls, cars are tilled at and non-stop or by-pass from their second stop in each instance. Upon car c by-passing the 14th landing, two remembered by-passed calls exist. Switch RVR will be actuated and car a caused to respond as described before. Upon by-pass ofthe 4th landing down call byy car c a total of six such calls exist and RVRX in accordance with its assumed operating value will now operate. Contacts RVRXil restore the detection facility for car b by completing a shunt path around open RVRl contacts.- Contacts RVRXZ close to determine release value of Current of switch coil RVRX. Contacts RVRX3 close to condi tion the Xi-lb switch circuits of car b to provide reversal control of that car at the highest remembered by-passed down call in a manner similar to that previously described for car a, by RVRS contacts.

It is now reasonable to assume that car a arrives and reverses at the 15th landing, stops at the 14th and is descending lpast the 12th landing loaded before car b arrives there. Assume in the meantime, a down call at 12 has been registered. The detection circuit of car a being oprative will give that call remembered by-passed status. The upward travel of -car b will then terminate at that landing in a manner similar to that formerly described for car a since its H control circuit with RVRXS contacts closed is dependent on the same column of RR@ contacts because of interconnecting wires between iii-i3d and RHb and so on up to and including Rl-Ila to Ri-ilb. Response of car a to the 15th and 14th calls cancelled them and thus released their memory relays lSRR and MRR leaving the newly established MRR as the highest for governing reversal of car b.

It should be noted that if car b was approaching the 12th as car a cancelled the call at the 14th release of MRR (not shown) would complete a circuit from supply positive terminal to RHllZb (not shown) permitting stop initiation and reversal of car b at the 12th landing without any actual call being remembered there, or in fact even registered at that landing.

Under the two stop full load limitation assumed above and consequent by-pass the remembered by-passed calls on iioors 9, 6 and 4 would not be served by initial trips of cars a and b. The succeeding trip of car a then would terminate upward travel at the 9th, and that of car b, assuming car a answered the 6th in descending, would terminate upward travel at the 4th landing.

It may be noted that car c is free to respond to any down calls during its descent but it may be safely assumed during this period it would be fully loaded at upper doors and hence would be by-passing lower floors. its detection circuit however is deactivated by open VRVRZ contacts to avoid affecting the reversal of cars a or b. Also cars a and b, if notloaded, are free to respond to any down calls between their reversal point and the lobby. The remembered -by-passed calls restrict only the upper reversal points of these cars.

Although six remembered by-passed calls were assumed as the basis of actuation of RVRX it should be noted a lesser number may accomplish thisk same purpose, in conjunction with additional energization of RVRX coil circuit through resistor RVTR. As described previously this may result from a prolonged existence of la lesser number of remembered by-passed calls or from simultaneous by-pass operation of more than one elevator. The former of these two alternatives would expedite transfer of car b if car arwas out of service. Conversely the RVRX circuit would be deactivated by CS'7c contacts being open it that car was out of service. A degree of insurance is thus provided againstrdepletion of service either at upper floors or at lower floors of the building as a result of removal of a car from group service. v i It can be seen from the foregoing description that for periods of intensive down trahie, as evidenced by bypassing of registered down landing calls, a control arrange- D @j ment is provided which distributes available service equitably to upper and lower portions of the building. In this period the number of cars is generally inadequate, tor economical reasons, to provide a quality of service comparable to that during other traffic periods of the day. The invention disclosed introduces, for this critical period, a variable division of the number of elevators of a group to assign one or more to serve upper floors in a conventional manner while assigning one or more other cars of the group to serve intermediate and lower oors in a downward progressive sequence with priority dictated by previouslyby-passed status of calls. Y

Although the preferred embodiment of the invention is disclosed for three cars it is equally appllicable to lesser numbers of cars or to greater numbers of cars.V It is applicable to a single car installation wherever it is desiredk to serve previously by-passed passengers before returning toV upper landingsl which may have had empty car privileges just prior to initiation of a by-pass operation.

As changes can be made in the above described construction and'many apparently diierent embodiments of this invention can be made without departing from the scope thereof, it is intended that all matter contained herein and on the accompanying'drawings be interpreted as illustrative only and not in a limiting sense.

What is claimed is:

l. in a control system for a plurality of elevator cars operating between a plurality of fioors, means at said floors `jor registering demands for service from higher floors to a lower floor, detecting means responsive to the bypassing by one of said cars of lioors at which service demands are registered when said car is on a trip travelling vfrom higher oors to said lower floor, memory means controlled by said detectingV means for registering the number of iioors so luy-passed by said car and means operated by said memory means when a plurality of bypassed iioors are registered by said memory means for dispatching a iirst car to the by-passed floor registered by said memory means which is the highest and then dispatching cars to successively lower ones ofthe floors by-passed by said car in preference to the other doors at which demands are registered.

2. in a control system for a plurality of elevator cars operating between a plurality ofiioors, means at said iioors for registering demands for service from higher iloors to a lower floor, detecting means responsive to the bypassing by any of said cars of floors at which service demands are registered when said car is on a trip travelling from higher iloors to said lower iloor, memory means controlled by said detecting means for registering the number of iioors so 1:Jy-passed by said car and means operated by said` memory means when a plurality of by-passed iioors are registered by said memory means for dispatching a rst car to the bypassed tloor registered by said memory means which is 'the highest and then dispatching cars to successively lower ones of the floors bypassed by said car in preference to other floors at which demands are registered. d

3. in an elevator control system having means for dispatching a plurality of cars from a terminal iloor and eans for registering demands for service at other floors and in the direction of said terminal floor, the combination therewith of means for detecting iioors at which said demands for service are bypassed by said cars, and means operated by said detecting means when at least a plurality of so by-passediioors have been detected by said detecting means and controlling said dispatching means for successively dispatching said cars to the by-passed klloor ot sai-d plurality of so bypassed floors farthest from said terminal which has been so by-passed and which has not received service from apreviously dispatched car andV for reversing the so dispatched car at said last-mentioned floor in both the presence and absence of registered demands for service at other iloors more remote from said terminal iioor than said by-passed door.

4. In a control system for a plurality of elevator cars operating between a plurality of fioors, means at a plurality of said fioors for registering demands for service in a predetermined direction from said floors, detecting means responsive to the by-passing by said cars of fioors at which a service demand is registered when on a trip travelling in said direction, memory means controlled by said detecting means for registering the number of doors so by-passed by said cars and means operated by said memory means when at least a plurality of by-passed iioors are registered by said memory means for stopping a car at the first of said by-passed tioors which is by-passed by a car on said trip and for preventing the stopping of said first-mentioned car at all other floors at which demands for service are registered subsequent to the bypassing of said first by-passed fioor until after said first mentioned car reaches said first of said by-passed ioors.

5. In a control system for a plurality of elevator cars operating between a plurality of fioors, means at a plurality of said fioors for registering demands for service in a predetermined direction, detecting means responsive to the by-passing of oors at which a service demand is registered when a car is travelling in said direction, first and second memory means controlled by said detecting means for registering the number of fioors so by-passed, and means operated by said first memory means when at least a tirst predetermined plurali-ty of so by-passed floors are registered by said first memory means for dispatching a car to, and reversing said last-mentioned car at, the fioor of said by-passed fioors which is most remote in a direction opposite to said predetermined direction and the registered demand of which has not been answered and operated by said second memory means when at least a second different predetermined plurality of so by-passed oors are registered by said second memory means for dispatching a car to, and reversing said last-mentioned car at, the fioor of said by-passed tloors which is most remote in a direction opposite to said predetermined direction and the registered demand of which has not been answered.

6. In a control system for a plurality of elevator cars operating between a plurality of fioors, means at a plurality of said oors for registering demands for service in a predetermined direction, detecting means responsive to the by-passing of fioors at which a service demand is registered when a car is travelling in said direction, first and second memory means controlled by said detecting means for registering the number of floors so by-passed, means operated by said first memory means when at least a tirst predetermined plurality of so by-passed floors are registered by said first memory means for dispatching a car to, and reversing said last mentioned car at, the floor of said by-passed oors which is most remote in a direction opposite to said predetermined direction and the registered demand of which has not been answered and operated by said second memory means when at least a second different predetermined plurality of so by-passed floors are registered by said second memory means tor dispatching a car to, and reversing said last-mentioned car at, the floor of said by-passed floors which is most remote in a direction `opposite to said predetermined direction and the registered demand of which has not been answered, and means interconnecting said rst and second memory means for causing operation of said dispatching means by said second memory means when said first predetermined plurality of so byapassed fioors has been registered by said first memory means for greater than a predetermined length of time and fewer than said second plurality of so by-passed floors are registered by said second memory means.

7. In a control system for a plurality of elevator cars operatingbetween a plurality of floors, means at a plurality of said fioors for registering demands for service in a predetermined direction, detecting means responsive to the by-passing of iioors at which a service demand is registered by said registered when a car is travelling in said direction, first and second memory means controlled by said detecting means for registering the number of floors so by-passed, means operated by said first memory means when at least a first predetermined plurality of so by-passed fioors are registered by said first memory means for dispatching a rst car to, and reversing said first car at, the fioor of said first by-passed fioors which is most remote in a direction opposite to said predetermined direction and the registered demand of which has not been answered and operated by said second memory means when at least a second different predetermined plurality of so by-passed floors are registered by said second memory means for dispatching a second car to, and reversing said second car at, the floor of said by-passed fioors which is most remote in a direction opposite to said predetermined direction and the registered demand of which has not been answered, and means interconnecting said first and second memory means for causing operation of said dispatching means by said second memory means and said dispatching and reversal of said second car when said first predetermined plurality of so by-passed iioors has been registered by said first memory means for greater than a predetermined length of time and less than said second plurality of so by-passed fioors are registered by said second memory means.

8. In a control system for at least three elevator cars, operating between a plurality of higher floors and a lower floor, means at said higher iioors for registering demands for service in the direction of said lower floor, detecting means responsive to the byapassing of said higher floors at which a service demand is registered when a car is travelling in said direction, first and second memory means controlled by said detecting means for registering the number of fioors so by-passed, means operated by said first memory means when at least two of so by-passed oors are registered by said first memory means for dispatching a first one of said cars to, and reversing said first car at, the highest door of said by-passed floors where the registered demand has not been answered and operated by said second memory means when a number of so bypassed fioors greater than two so by-passed fioors are registered by said second memory means for dispatching a second one of said cars to, and reversing said second car at, the highest of said so by-passed floors where the registered demand has not been answered, means interconnecting said first and second memory means for causing operation of said dispatching means by said second memory means and dispatching of said second car to, and reversing said second car at, the highest of said so bypassed fioors where a registered demand has not been answered when at least two so by-passed iloors have been first memory means for greater than a predetermined length of time and less than said greater number of so by-passed floors are registered by said second memory means, and means for preventing reversal of the third one of said cars under control of said first and second memory means.

9. In a control system for a plurality of elevator cars operating between a dispatching floor and a plurality of other floors, means at said other fioors for registering demands for service in the direction of said dispatching fioor, means for detecting the registered demands at said 'other fioors which have been by-passed by a car, memory means responsive to said detecting means for registering a plurality of said by-passed registered demands which have been detected by said detecting means, and means operated by said memory means when a predetermined plurality of by-passed registered demands, less in number than said .plurality of other fioors, have been registered by said memory means, for dispatching a car at said dispatching tioor to the by-passed fioor most remote from said dispatching floor having a registered demand which is one of said predetermined plurality of demands in preference to floors having registered demands but which are ener/,sas

li l more remote from said dispatching floor than Said bypassed door.

lil. in a control system for an elevator car operating between a dispatching iioor and a plurality of other doors, means at said other floors for registering demands for service in the direction of said dispatching floor, means for detecting the registered demands at said other doors which have been by-passed by a car, memory means responsive to said detecting means for registering a plurality oi said by-passed registered demands which have been detected by said detecting means, and means operated by said memory means when a predetermined plurality of by-passed registered demands, less in number than said plurality of other iloors, have been registered by said memory means, for dispatching said car from said dispatching floor to the lay-passed floor moet remote from said dispatching floor having a registered demand which is one of said predetermined plurality of demands in preferance to doors' having registered demands but which are more remote from said dispatching door than said bypassed door.

ll. In a control system for a plurality of elevator' cars operating between a dispatching door and a plurality of other floors, means at said other floors for registering demands for service in the direction of said dispatching door, means for detecting predetermined registered demands difrering from other registered demands, means operated by said detecting means when a plurality of said predetermined demands, less in number than :the number of said other floors, are detected by said detecting means for successively dispatching cars from said dispatching iioor, in both the presence and absence of other registered demands corresponding to tloors which are more remote from said dispatching door than the iloors corresponding Eto said plurality ot predetermined demands, to the doors most remote from said dispatching tloor which corresponds to said plurality of demands but to which a previously i dispatched car has not been dispatched.

l2. ln a control system for a plurality of elevator cars operating between a plurality of floors, means at said floors for registering demands for service in a predetermined direction, means for detecting predetermined registered demands to which a car has tailed to respond, memory means controlled by said detecting means for registering said predetermined registered demands, and means operated by said memory means when a plurality of said predetermined demands, less in number than `the number of said floors, are registered by said memory means for causing cars to answer, in both the presence and absence of other registered demands corresponding to oors which are more remote in the direction opposite to said predetermined direction than the floors corresponding to said plurality of predetermined demands, the demand of said plurality of demands registered by said memory means and which is most remote in said direction opposite to said predetermined direction.

13. ln a control system for a plurality of elevator car-s operating between a plurality of floors, said Ysystem comprising means for registering demands for service in a predetermined direction, predetermined registered ones of said demands having a status different from others of said demands, the combination therewith of means for detecting and registering a plurality of said different status demand-s, means operated by said last-mentioned means when a predetermined plurality of said different status demands, less in number than the number of said plurality of floors, are registered by said last-mentioned means for causing a car to answer iirst the demand of said predetermined plurality of demands which is most remote in the direction opposite to said predetermined direction in both the presence and absence or" other registered demands more remote than said demand `and which are not said predetermined plurality of demands.

Cil

Y l2. means for registering demands for service in -a predetermined direction, predetermined registered ones of said demands having a status ditierent'from other-s of said demands, the combination therewith o means for detecting and registering a plurality of vsaid diiterent status demands, means operated by said last-mentioned means when a predetermined rplurality of said different status demands, less in number than the number of said plurality of ioors, are registered by said last-rnentioned means for causing said car to answer iirst the demand of said predetermined plurality of demands which is most remote in a direction opposite to said predetermined direction in both Vthe [presence yand absence of other registered demands more remote than said demand and which are not said predetermined plurality of demands.

l5. In a control system for a plurality of elevator ears operating between a plurality of floors, said system comprising means for registering Vdemands for service in a predetermined direction, predetermined registered ones of said demands having a status different from others of said demands, the combination therewith of means for detecting and registering ia plurality of said different status demands, means operated by. said last-mentioned means when a predetermined plurality of said different status demands, less in number than the number of said plurality of iloors, are registered by said'last-irnentioned means for Vcausing a rst car toV answer iirst the demand of said predetermined plurality ozf demands which is most remote ina direction opposite to said predetermined direction in both the presence and absence of other registered demands more remote than said demand and which are not said predetermined plurality of demands and to answer thereafter registered demands which are less remote than said demand and for causing cars subsequently available to answer demands and less in number than said plurality of cars, to answer Vin succession the demand of sia-id predetermined plurality of demands which is moet remote in said direction opposite to said predetermined direction and which has not been answered by a previously ava-ilable rear in both the presence and absence of other registered demands, which are not said .predetermined plurality of demands.

liti. In a control system for an elevator car operating between a plurality of Floors, said system comprising means for registering demands for service in a predetermined direction, predetermined registered ones of said demands having a status different from others of said demands, the combination therewith of means for detecting and registering .a plurality of said different status demands, means operated by said last-mentioned means when a predetermined plurality of said different status demands, less in number than the number of said plurality of floors, are registered by said last-mentioned means for causing said car to answer tirst the demand of said predetermined plurali-ty of demands which is most remote in a direct-ion yopposite to said predetermined direction in both the presence and absence of other registered demands more remote `than said demand and Vwhich are not said predetermined plurality of demands .and to answer thereafter registered demands which are less remote than said dern-and and for a car on a subsequent trip to answer the demand oi said predetermined plurality of demands which is most remote in said direction opposite to saidV predetermined direction and which has not been answered by said car.

References (Cited by the Examiner UNITED STATES PATENTS 2,621,759 12/52 VEsselman IS7-29 2,624,425 l/53' Eames 187-29 3,022,866 2/62 Bailey 187--29 O'RlS KADER, Primary Examiner.

MILTON O. HlRSHFlELD, Examiner. 

3. IN AN ELEVATOR CONTROL SYSTEM HAVING MEANS FOR DISPATCHING A PLURALITY OF CARS FROM A TERMINAL FLOOR AND MEANS FOR REGISTERING DEMANDS FOR SERVICE AT OTHER FLOORS AND IN THE DIRECTION OF SAID TERMINAL FLOOR, THE COMBINATION THEREWITH OF MEANS FOR DETECTING FLOORS AT WHICH SAID DEMANDS FOR SERVICE ARE BY-PASSED BY SAID CARS, AND MEANS OPERATED BY SAID DETECTING MEANS WHEN AT LEAST A PLURALITY OF SO BY-PASSED FLOORS HAVE BEEN DETECTED BY SAID DETECTING MEANS AND CONTROLLING SAID DISPATCHING MEANS FOR SUCCESSIVELY DISPATCHING SAID CARS TO THE BY-PASSED FLOOR OF SAID PLURALITY OF SO BY-PASSED FLOORS FARTHEST FROM SAID TERMINAL WHICH HAS BEEN SO BY-PASSED AND WHICH HAS NOT RECEIVED SERVICE FROM A PREVIOUSLY DISPATCHED CAR AND FOR REVERSING THE SO DISPATCHED CAR AT SAID LAST-MENTIONED FLOOR IN BOTH THE PRESENCE AND ABSENCE OF REGISTERED DEMANDS FOR SERVIVE AT OTHER FLOORS MORE REMOTE FROM SAID TERMINAL FLOOR THAN SAID BY-PASSED FLOOR. 